宽带反射膜的优化设计和性能分析（英文）

Optimization Design and Performance Analysis of The Broadband High-reflective Coatings

宽带反射膜存在着材料折射率有限、反射带宽和反射率不能满足需要、制备过程中薄膜的厚度和折射率难以精确控制等重要的问题。为了满足光学元件对宽光谱反射的要求,采用多个膜堆结构展宽反射带的方法,使用TFCalc优化设计膜系,对膜系结构参数进行不断地改进和调整,设计了带宽为400-900nm、入射角分别为0°和60°的两种全介质多层反射膜并且对其性能进行了分析。结果表明,入射角为0°的宽带反射膜平均反射率达到99.6%,入射角为60°的宽带反射膜平均反射率达到98.6%,这两种反射膜均可以在超宽光谱范围内提高光学仪器的反射率;膜系的中心波长、电场强度分布、平均反射率和反射带宽受入射角度影响,在平均反射率和反射带宽方面,60°入射的膜系比0°入射的膜系受入射角度的影响更大。

There are some key problems about the broadband high-reflective coatings,such as the limit of the refractive index of the material,the dissatisfaction of needs for higher reflectance and wider reflective bandwidth,and the uncontrolling of the accuracy of the the thickness and the refractive index of the layers in the preparation process.To satisfy the requirements of optical elements for wide spectral reflection,the reflection wavelength region of the coatings was widen by using multiple stacks.The design and optimization was based on the software of TFCalc.By improvements and adjustmets continuously to the coatings structure parameters,two kind of all-dielectric multilayer high-reflective coatings were designed,which can be used in the same high-reflection wavelength region of 400-900 nm but with different incident angles of 0°and 60°,and their performances were analyzed.The result shows that the average reflectance of the broadband high-reflective coatings with an incident angle of 0°reaches 99.6%,and the average reflectance of the one with an incident angle of 60°is 98.6%.Both of the two high-reflective coatings can well improve the reflectance of the optical instruments within supper broadband bandwidth.The central wavelength,the distributions of the electric field,the average reflectance and the high reflection bandwidth of the coatings are all affected by the incident angle,and the influence on the 60°incidence coatings is obviously greater than that on the 0°incidence coatings in the aspects of average reflectance and the high reflection bandwidth.